Bosch drives down fuel consumption - in a salami technique

June 14, 2013 //
By Christoph Hammerschmidt

During its biennial Motor Press Colloquium press event, automotive supplier Bosch gave insights into major development currents in automotive electronics. One of the focus topics was the power train and ways to further reduce fuel consumption and CO2 emission.

The powertrains will continue to evolve towards better fuel efficiency for the combustion engines and better batteries for their electric counterparts. For instance, Bosch expects Lithium-ion batteries which deliver twice the power compared to today's models - at 50 % lower prices, explained Bernd Bohr, General Manager of Bosch's automotive technology division. The company continues to bet on electromobility - but not for all vehicle classes. Electric powertrains, be it hybrid or fully electric, can unfold their potential in large, heavy vehicles rather than in subcompacts, Bohr said. As a consequence, in the subcompact category with conventional engines will be further optimized to meet the EU CO2 targets for 2020 even without electric drives. Large cars, in contrast won't be able to meet these CO2 targets not even with optimized combustion engines. They require powerful electric components for hybrid drives.

To meet these targets for both ICE and hybrid electric powertrains, Bosch is developing a number of components that help to reduce CO2 emissions. Among them is an electric clutch (which already was demonstrated at the event) that automatizes manual transmissions: When the driver takes his foot off the accelerator pedal, the new eClutch switches the transmission into idle, causing the vehicle to coast along at low engine speed. This device will reduce fuel consumption by 5 %, Bohr believes.

In addition, the start-stop system in micro and full hybrid systems will receive data input from the navigation system. "Thus, the navigation will act as a sensor to topology", Bohr explained. The effect: The system reduces the vehicle speed early ahead of speed limits or curves. Bohr estimates that this approach will reduce fuel consumption by as much as 15%. Optimized hybrid components and systems with a new feature called Boost Recuperation System (BRS) will add regenerative braking, saving up to 7% of the fuel.

Another approach is the hydraulic hybrid system Bosch currently develops along with French carmaker PSA.